Switch to libunwind to remove dependency on libgcc for musl am: 441898c285

Original change: https://android-review.googlesource.com/c/platform/build/soong/+/1983628

Change-Id: I1520b92b0fa7a3266915cd20dd45019df761a849
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>

cc/config/x86_linux_host.go

@@ -65,7 +65,6 @@ var (
 
 	linuxMuslLdflags = []string{
 		"-nostdlib",
-		"-lgcc", "-lgcc_eh",
 		"--sysroot /dev/null",
 	}
 

rust/config/x86_linux_host.go

@@ -42,8 +42,6 @@ var (
 		"-nodefaultlibs",
 		"-nostdlib",
 		"-Wl,--no-dynamic-linker",
-		// for unwind
-		"-lgcc", "-lgcc_eh",
 	}
 	linuxX86Rustflags   = []string{}
 	linuxX86Linkflags   = []string{}